I am having the same issue and tried the default cycling sport mode as suggested by olson with the power option. I also lost connectivity with my other power meter on my MTB bike, tried a soft reset, tried unpairing and re-pairing, unpairing my HR monitor
as clemens found, I can pair set crank length and see power in the power meter at 85%. when i leave the set up mode and go to sport mode it is not connecting